New Adaptive Sliding Mode for Unperturbed Forearm and Wrist Rehabilitation Robot

The paper put forth presents the design and validation of a novel adaptive, variable gain, sliding mode control (SMC) reaching law, for the purpose of controlling unperturbed nonlinear systems. The novelty of this law stems from its capability to overcome the main limitations involved with conventional SMCs. In contrast to existing reaching laws, the presented law is potentially able to achieve high system performance, reduce the chattering problem significantly, and ensure fast convergence of system trajectories to equilibrium. The designed law integrates the features of both, the exponential reaching law (ERL) and the power rate reaching law (PRL), meanwhile, it overcomes their limitations. Simulation and comparison case studies against ERL and PRL are also carried out with Forearm and Wrist Rehabilitation Robot to validate the effectiveness and advantages of the proposed reaching law scheme (Proposed RL).